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Dadsetan M, Taylor KE, Yong C, Bajzer Ž, Lu L, Yaszemski MJ. Controlled release of doxorubicin from pH-responsive microgels. Acta Biomater 2013; 9:5438-46. [PMID: 23022545 PMCID: PMC3970914 DOI: 10.1016/j.actbio.2012.09.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/13/2012] [Accepted: 09/18/2012] [Indexed: 10/27/2022]
Abstract
Stimuli-responsive hydrogels have enormous potential in drug delivery applications. They can be used for site-specific drug delivery due to environmental variables in the body such as pH and temperature. In this study, we have developed pH-responsive microgels for the delivery of doxorubicin (DOX) in order to optimize its anti-tumor activity while minimizing its systemic toxicity. We used a copolymer of oligo(polyethylene glycol) fumarate (OPF) and sodium methacrylate (SMA) to fabricate the pH-responsive microgels. We demonstrated that the microgels were negatively charged, and the amounts of charge on the microgels were correlated with the SMA concentration in their formulation. The resulting microgels exhibited sensitivity to the pH and ionic strength of the surrounding environment. We demonstrated that DOX was efficiently loaded into the microgels and released in a controlled fashion via an ion-exchange mechanism. Our data revealed that the DOX release was influenced by the pH and ionic strength of the solution. Moreover, we designed a phenomenological mathematical model, based on a stretched exponential function, to quantitatively analyze the cumulative release of DOX. We found a linear correlation between the maximum release of DOX calculated from the model and the SMA concentration in the microgel formulation. The anti-tumor activity of the released DOX was assessed using a human chordoma cell line. Our data revealed that OPF-SMA microgels prolonged the cell killing effect of DOX.
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Affiliation(s)
- Mahrokh Dadsetan
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - K. Efua Taylor
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Chun Yong
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Željko Bajzer
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Lichun Lu
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Michael J. Yaszemski
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Meyers SR, Kenan DJ, Khoo X, Grinstaff MW. Bioactive stent surface coating that promotes endothelialization while preventing platelet adhesion. Biomacromolecules 2011; 12:533-9. [PMID: 21218765 DOI: 10.1021/bm101212k] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A bifunctional peptide coating was designed, synthesized, and evaluated as a potential pro-healing stent coating. The bifunctional peptide consisted of a short 28-mer sequence that on the N-terminus has a motif with affinity for polystyrene binding and at the C-terminus has a motif that was shown to bind selectively human endothelial cells but not platelets. Results showed that the selective coating, a polystyrene-binding peptide terminated in RRETAWA (FFSFFFPASAWGSSGSSGK(biotin)CRRETAWAC), bound endothelial cells quantitatively as well as the common RGD motif, but unlike RGD, it did not show any preference for platelet adherence. Follow-up work examining the difference in cell line selectivity between endothelial cells, whose binding should be encouraged, and smooth muscle cells, whose binding should be deprecated in a stenting application, did identify a temporal preference of the RRETAWA-terminated peptide coating for endothelial cells. However, the in vivo implications of this apparent selectivity need to be examined in more detail before definitive conclusions can be drawn. The positive in vitro results encourage the continued development of other novel coatings that mimic biological structures, signaling capabilities, or both to direct cellular processes on the surface of synthetic materials.
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Affiliation(s)
- Steven R Meyers
- Department of Biomedical Engineering, Metcalf Center for Science and Engineering, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA
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You JO, Almeda D, Ye GJC, Auguste DT. Bioresponsive matrices in drug delivery. J Biol Eng 2010; 4:15. [PMID: 21114841 PMCID: PMC3002303 DOI: 10.1186/1754-1611-4-15] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 11/29/2010] [Indexed: 02/10/2023] Open
Abstract
For years, the field of drug delivery has focused on (1) controlling the release of a therapeutic and (2) targeting the therapeutic to a specific cell type. These research endeavors have concentrated mainly on the development of new degradable polymers and molecule-labeled drug delivery vehicles. Recent interest in biomaterials that respond to their environment have opened new methods to trigger the release of drugs and localize the therapeutic within a particular site. These novel biomaterials, usually termed "smart" or "intelligent", are able to deliver a therapeutic agent based on either environmental cues or a remote stimulus. Stimuli-responsive materials could potentially elicit a therapeutically effective dose without adverse side effects. Polymers responding to different stimuli, such as pH, light, temperature, ultrasound, magnetism, or biomolecules have been investigated as potential drug delivery vehicles. This review describes the most recent advances in "smart" drug delivery systems that respond to one or multiple stimuli.
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Affiliation(s)
- Jin-Oh You
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Dariela Almeda
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - George JC Ye
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Debra T Auguste
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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Khoo X, O'Toole GA, Nair SA, Snyder BD, Kenan DJ, Grinstaff MW. Staphylococcus aureus resistance on titanium coated with multivalent PEGylated-peptides. Biomaterials 2010; 31:9285-92. [PMID: 20863561 DOI: 10.1016/j.biomaterials.2010.08.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 08/16/2010] [Indexed: 11/30/2022]
Abstract
Bacterial infections can have adverse effects on the efficacy, lifetime and safety of an implanted device and are the second most commonly attributed cause of orthopedic implant failure. We have previously shown the assembly of PEGylated titanium-binding peptides (TBPs) on Ti to obtain a bacteriophobic surface coating that can effectively resist protein adsorption and Staphylococcus aureus (S. aureus) adhesion. In the present study, we examine the effect of multiple TBP repeats on coating performance in vitro. Mono, di, and tetravalent peptides were synthesized and assessed for binding affinity and serum stability. PEGylated analogs were prepared and evaluated for their effect on S. aureus attachment and biofilm formation. Coating performance improved with the number of TBP repeats, with the tetravalent coating, TBP(4)-PEG, showing the best performance in all assays. In particular, TBP(4)-PEG forms a serum-resistant surface coating capable of preventing S. aureus colonization and subsequent biofilm formation. These results further support the role that multivalency can play in the development of improved surface coatings with enhanced stabilities and efficacy for in vivo clinical use.
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Affiliation(s)
- Xiaojuan Khoo
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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Khoo X, Hamilton P, O’Toole GA, Snyder BD, Kenan DJ, Grinstaff MW. Directed Assembly of PEGylated-Peptide Coatings for Infection-Resistant Titanium Metal. J Am Chem Soc 2009; 131:10992-7. [DOI: 10.1021/ja9020827] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Xiaojuan Khoo
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Paul Hamilton
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - George A. O’Toole
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Brian D. Snyder
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Daniel J. Kenan
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Mark W. Grinstaff
- Departments of Biomedical Engineering and Chemistry, Boston University, Boston, Massachusetts 02215, Affinergy, Inc., Durham, North Carolina 27713, Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Orthopedic Surgery, Children’s Hospital, Harvard Medical School, Boston, Massachusetts 02215, and Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
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